diff --git a/backend/src/main/java/de/hft/geotime/controllers/RecordController.java b/backend/src/main/java/de/hft/geotime/controllers/RecordController.java
index 716aaba..88bfb28 100644
--- a/backend/src/main/java/de/hft/geotime/controllers/RecordController.java
+++ b/backend/src/main/java/de/hft/geotime/controllers/RecordController.java
@@ -1,26 +1,60 @@
 package de.hft.geotime.controllers;
 
+import de.hft.geotime.entities.RecordType;
+import de.hft.geotime.entities.TimeRecord;
+import de.hft.geotime.entities.TimetrackAccount;
 import de.hft.geotime.repositories.RecordRepository;
-import de.hft.geotime.repositories.TimetrackUserRepository;
-import org.springframework.data.projection.ProjectionFactory;
+import de.hft.geotime.repositories.TimetrackAccountRepository;
+import org.springframework.data.domain.Page;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import java.time.LocalDateTime;
+import java.util.Optional;
+
 @RestController
 public class RecordController {
 
     private final RecordRepository recordRepository;
-    private final TimetrackUserRepository userRepository;
-    private final ProjectionFactory projectionFactory;
+    private final TimetrackAccountRepository accountRepository;
 
-    public RecordController(RecordRepository recordRepository, TimetrackUserRepository userRepository, ProjectionFactory projectionFactory) {
+    public RecordController(RecordRepository recordRepository, TimetrackAccountRepository accountRepository) {
         this.recordRepository = recordRepository;
-        this.userRepository = userRepository;
-        this.projectionFactory = projectionFactory;
+        this.accountRepository = accountRepository;
     }
 
     @GetMapping("/track")
-    public void track() {
-        //"/track?accountid=bla" → start/stop recording for that account
+    public ResponseEntity<TimeRecord> track(@RequestParam String account, Authentication authentication) {
+        if (account == null || account.isEmpty()) {
+            return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
+        }
+
+        TimetrackAccount selectedAccount = accountRepository.findByUser_UsernameAndName(authentication.getName(), account);
+
+        if (selectedAccount == null) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        Page<TimeRecord> entires = recordRepository.findAllByEnddateIsNull(null);
+        Optional<TimeRecord> collect = entires.stream()
+                .filter(timeRecord -> timeRecord.getAccount().equals(selectedAccount))
+                .findFirst();
+
+        if (collect.isPresent()) {
+            collect.get().setEnddate(LocalDateTime.now());
+            recordRepository.save(collect.get());
+            return new ResponseEntity<>(collect.get(), HttpStatus.OK);
+        } else {
+            TimeRecord newRecord = new TimeRecord();
+            newRecord.setType(RecordType.PAID);
+            newRecord.setStartdate(LocalDateTime.now());
+            newRecord.setAccount(accountRepository.findByUser_UsernameAndName(authentication.getName(), account));
+            recordRepository.save(newRecord);
+            return new ResponseEntity<>(newRecord, HttpStatus.CREATED);
+        }
     }
 }
diff --git a/backend/src/main/java/de/hft/geotime/entities/TimeRecord.java b/backend/src/main/java/de/hft/geotime/entities/TimeRecord.java
index b1914cd..ef08904 100644
--- a/backend/src/main/java/de/hft/geotime/entities/TimeRecord.java
+++ b/backend/src/main/java/de/hft/geotime/entities/TimeRecord.java
@@ -30,7 +30,11 @@ public class TimeRecord {
     private RecordType type;
 
     public long getDuration() {
-        return startdate.until(enddate, ChronoUnit.MINUTES);
+        if (enddate == null) {
+            return 0;
+        } else {
+            return startdate.until(enddate, ChronoUnit.MINUTES);
+        }
     }
 
 }
diff --git a/backend/src/main/java/de/hft/geotime/entities/TimetrackAccount.java b/backend/src/main/java/de/hft/geotime/entities/TimetrackAccount.java
index 58d7cc2..0c2e89a 100644
--- a/backend/src/main/java/de/hft/geotime/entities/TimetrackAccount.java
+++ b/backend/src/main/java/de/hft/geotime/entities/TimetrackAccount.java
@@ -6,7 +6,6 @@ import lombok.Data;
 import lombok.NoArgsConstructor;
 
 import javax.persistence.*;
-import java.util.List;
 
 @Data
 @NoArgsConstructor
@@ -25,7 +24,4 @@ public class TimetrackAccount {
     @ManyToOne
     private TimetrackUser user;
 
-    @OneToMany(mappedBy = "account")
-    private List<TimeRecord> records;
-
 }
diff --git a/backend/src/main/java/de/hft/geotime/repositories/RecordRepository.java b/backend/src/main/java/de/hft/geotime/repositories/RecordRepository.java
index 2191a80..71c04f6 100644
--- a/backend/src/main/java/de/hft/geotime/repositories/RecordRepository.java
+++ b/backend/src/main/java/de/hft/geotime/repositories/RecordRepository.java
@@ -48,4 +48,7 @@ public interface RecordRepository extends PagingAndSortingRepository<TimeRecord,
     @Query("SELECT record from TimeRecord record where record.account.user.username = :#{principal} AND record.startdate > (current_date-1)")
     Page<TimeRecord> today(Pageable pageable);
 
+    @RestResource(rel = "openEntries", path = "openEntries")
+    Page<TimeRecord> findAllByEnddateIsNull(Pageable pageable);
+
 }
diff --git a/backend/src/main/java/de/hft/geotime/repositories/TimetrackAccountRepository.java b/backend/src/main/java/de/hft/geotime/repositories/TimetrackAccountRepository.java
index 81075a5..df69761 100644
--- a/backend/src/main/java/de/hft/geotime/repositories/TimetrackAccountRepository.java
+++ b/backend/src/main/java/de/hft/geotime/repositories/TimetrackAccountRepository.java
@@ -3,6 +3,7 @@ package de.hft.geotime.repositories;
 import de.hft.geotime.entities.TimetrackAccount;
 import org.springframework.data.repository.PagingAndSortingRepository;
 import org.springframework.data.rest.core.annotation.RepositoryRestResource;
+import org.springframework.data.rest.core.annotation.RestResource;
 
 @RepositoryRestResource(
         path = "accounts",
@@ -11,4 +12,7 @@ import org.springframework.data.rest.core.annotation.RepositoryRestResource;
 )
 public interface TimetrackAccountRepository extends PagingAndSortingRepository<TimetrackAccount, Long> {
 
+    @RestResource(rel = "findByUsernameAndName", path = "findByUsernameAndName")
+    TimetrackAccount findByUser_UsernameAndName(String username, String account);
+
 }